The present application is generally related to large bearing cage configurations, and in particular, but not exclusively, to a cage assembly for a large diameter bearing containing multiple heavy rolling elements and including discrete bridge elements coupled between axially-spaced cage wire rings located adjacent opposite axial ends of the rolling elements.
The usual approach to designing large-bearing cages (typically 1-4 meters in diameter) has been to extend the design styles for smaller, conventional bearings to the larger bearing sizes. The first and most common attempt at meeting the needs of larger bearings uses pin style cages to facilitate placement and retention of the rolling elements. While pin style cages provide excellent retention, they are heavy, complex, and costly to assemble. Furthermore, some pin style cage designs can partially block flow of lubricants (especially grease) to critical wear surfaces. They also cannot be disassembled without damaging either the cage rings or the cage pins.
Another cage design often considered is an “L” type design produced using various combinations of forging, forming, machining and precision cutting. The resulting cost of bearing cages produced using combinations of these various processes are unacceptably high, especially for the larger bearing sizes.
Yet another cage design is a polymer segmented style cage. While these cages have a demonstrated ability to perform satisfactorily, there are potential limitations in scaling up this design for larger bearings containing heavy rollers. Current polymer cages for very large bearings are made from polyether ether ketone (PEEK), an organic polymer thermoplastic which is relatively expensive. For extremely large bearings containing large rollers, the size and strength of the cage must be increased. The greater amount of PEEK required to make a sufficiently strong cage can therefore often be cost prohibitive. Accordingly, polymer segmented cages appear to be most suited for bearing cages with small to medium size rollers which only require small to medium size PEEK segments.
Based on the foregoing, it would be advantageous to provide a large bearing cage design having full functionality (roller retention, roller spacing, roller alignment, lubricant flow) for various sizes and types of bearings (e.g., tapered roller, cylindrical roller, spherical roller bearings, etc.) and which can be manufactured at a lower cost than is currently possible.